1. Technical Field of the Invention
The present invention relates to a loop material of a hook-and-loop fastener serving as a fastener and, more particularly, to a loop material of a hook-and-loop fastener applied to disposable goods such as diapers, operating gowns, and the like. The present invention relates also to a manufacturing process of such a loop material of a hook-and-loop fastener.
2. Prior Art
A hook-and-loop fastener comprises a sheet-like or tape-like loop material having a large number of loop-shaped or arch-shaped engaged members on its surface and a sheet-like or tape-like hook material having a large number of mushroom-shaped or hook-shaped projections on its surface, and provides a fastener function by engaging the projections of the hook material with the engaged members of the loop material. The hook-and-loop fastener is employed in a varieties of uses such as clothing, daily necessaries, interior materials, industrial materials, etc., because of its simple and easy way of use, as compared with other fasteners.
Generally, a sheet or tape of synthetic resin such as nylon, polyethylene, polypropylene, on the surface of which a large number of mushroom-shaped or hook-shaped projections are formed, is employed as a hook material On the other hand, a pile woven or knitted fabric having a large number of loops (piles) on its surface which is obtained by weaving or knitting synthetic multifilaments or monofilaments of nylon, polyester, polypropylene, etc., is employed as a loop material.
When joining by pressing such a hook material to a loop material, very high joining strength (high peeling strength and high shearing strength) may be obtained. Even when repeating the joining by pressing, the high joining strength may be maintained, and the hook-and-loop fastener has high joining durability.
However, when a hook-and-loop fastener is applied to disposable goods such as diapers, operating gowns, the hook-and-loop fastener is in most cases thrown away after one time or several times of use together with the disposable goods, and therefore the high joining durability is not always required. It may be said that the application of the mentioned hook-and-loop fastener to the disposable goods is more than enough quality and is not always reasonable. Since the quality is more than enough, the price is high, and therefore the application of the high quality hook-and-loop fastener to disposable goods is not economical.
Under such circumstances, several hook and hoop materials of a hook-and-loop fastener for use in disposable goods such as diapers, operating gowns, etc., have been heretofore proposed. In particular, a loop material composed of filamentous nonwoven fabric having wrinkle portions (Japanese Patent Laid-Open Patent Publication No. 6-33359) and another loop material composed of a nonwoven fabric on the surface of which loops are formed by needle-punching a nonwoven web (Japanese Patent Laid-Open Patent Publication No. 7-171011 and 9-317) were proposed. The loop materials composed of the above-mentioned nonwoven fabrics are economical from the viewpoint of price, and not having high joining durability, the loop materials are suitable for disposable goods.
However, since the projections of the hook material are engaged with the wrinkle portions or loop portions which are formed of filaments or fibers, there is a disadvantage of poor joining strength. That is, since the surface of the filament or fiber is generally smooth and the coefficient of friction thereof is small, there arises a problem that the projections of the hook material once engaged are easy to remove from the loops so that it is difficult to obtain high joining strength. Accordingly, when such a loop material is applied to the hook material for engagement, there is a disadvantage that if a shearing load (external load produced horizontally in the face direction of the hook material and loop material) or a peeling load (external load produced vertically in the face direction of the hook material and loop material) is applied after joining, the hook and loop materials are disjoined from each other. It is certain that high joining durability is not required in the disposable goods, but high joining strength is essential
Accordingly, an object of the present invention is to provide a loop material of a hook-and-loop fastener composed of a nonwoven fabric in which a surface of the loop (hereinafter referred to as xe2x80x9cloop surfacexe2x80x9d) formed at least on one face of the nonwoven fabric is made unevenly by various means so that the coefficient of friction between the projections and loops may be increased, whereby the projections are hard to remove from the loops after engagement with each other.
To accomplish the foregoing object, means are provided for making the surface of the loop uneven by applying an antislipping agent to the loop surface, and a means for making the surface of the loop uneven by employing conjugate filaments or fibers composed of a low melting point polymer and a high melting point polymer as filaments or fibers forming the loop in which the low melting point polymer is deformed by softening or melting.
The former is a loop material of a hook-and-loop fastener composed of a base of nonwoven fabric formed by accumulating a large number of filaments or fibers, and a large number of loops formed by partially protruding the filaments or fibers at least on one plane side of the nonwoven base, and an antislipping agent is applied to at least one part of each loop surface.
On the other hand, the latter is a loop material of a hook-and-loop fastener composed of a base of nonwoven fabric formed by accumulating conjugate filaments or fibers each of which is formed of a high melting point polymer and a low melting point polymer occupying at least one part of the surface of the filament or fiber, and a large number of loops formed by partially protruding the filaments or fibers at least on one plane side of the nonwoven base, and unevenness of the surface of the loop is formed by softening or melting the low melting point polymer.